Windows Explorer on Windows 7 tries to be intelligent and offers to group the contents of a directory according to certain parameters. A lot of times when it cannot do this, it lumps them in a group named Unspecified. I find this grouping affair very irritating, especially when selecting files using the keyboard.
To turn off Group By completely:
- Open any directory in Windows Explorer.
- Right-click and choose Group by → (None)
- Press the Alt key, so that the Explorer menu bar appears and choose Tools → Folder Options.
- Go to the View tab and click Apply to Folders. This will apply the Group By setting to all folders.